There is NO best mech design for everything. A Direwolf won't be able to complete a mission that requires sustained speeds of 80+ kph. A Firemoth (Dasher) <probably> won't survive a meat-grinder mission (6+ enemy mechs attacking at the same time). A 65ton mech could do both missions, but won't be the best choice for either of them. Sometimes you need speed, sometimes you need lots of heavy weapons, and sometimes you need armor. You CAN'T have maximum in all of them!

Some mechs are easily headshot, killing them. Examples of headshot-prone mechs are: Catapult, DireWolf, Firemoth, Jenner, Nova, Sentinel, Stalker, Urbanmech. Man-walker designs tend to be LESS headshot prone than other mechs. I don't think I've ever gotten a headshot kill on a Loki or a Thor! Although a DIREWOLF is slightly headshot prone, it has the MOST free critical slots of ANY MECH in its Standard configuration!

A standard Annihilator is easy to kill because it is VERY lightly armored, VERY slow, has lots of ammo and no CASE (resulting in ammo exploisions), and has few weapons. It's a stupid design, but that's not the mech chassis's fault! The Annihilator is SMALLER and harder to hit than an Atlas, Direwolf, or Kodiak! This can be CRITICAL in a high-lag MercNet game. No hand Actuators on an Annihilator - more free slots for weapons! With a bigger engine and jump-jets, it moves as fast as an ATLAS. Many think Annihilators suck, and might forget caution until too late to save themselves! Last but not least, it's 100 tons, same as an Atlas!

Put full armor on your mech's head and torso sections, with at least 6 points of armor on your mech's back for backstabbing opponents! Its a GOOD IDEA to put full armor elsewhere as well. Too many standard mechs do NOT have full armor and are easily killed - like the Naga and Annihilator for instance. Add .5 tons armor to every mech you get (especially your starting mech), but only use 3 points of armor -- not the full 8 it gives. Once you click on another component, the .5 tons of added weight goes away but the armor DOESN'T! Add 4 points of armor to clan mechs with ferro-fiberous armor, and the mechs won't gain any weight!

Put LASERS in your mech's head and central torso, preferably medium lasers or ER SMALL Lasers (if clan), medium lasers (if IS). This will give you LAST-DITCH weapons if you find your mech shot to pieces by a LUCKY foe. ALSO, add a flamer somewhere to your mech - preferably to your mech's torso or legs, so you have it almost till you die! Put most, if not ALL of your weapons in your head, central torso, legs, and side torsos (in THAT order) because they're the best-protected parts of your mech.

In MercNet games, high-heat weapons like LARGE PULSE LASERS and erPPCs might as well be in the arms with most of the heatsinks on the mech because IF you lose your arms, you're NOT going to have enough heatsinks left to effectively use them (and your enemies are probably close.) This may encourage your opponents to shoot at your arms instead of shooting at YOU! In a single-player game however, put the weapons somewhere where they're less likely to be destroyed - like the legs instead.

Sell your starting mech and buy a CRAB (or some other BIGGER mech) immediately after completing one or 2 Merc Contracts. If you bought a Crab, lose the large laser in the left arm (and SELL it), and that should free up 5 tons weight. Use that weight for more armor, jump-jets, and heat sinks. Don't hire any starmates until you gain salvaged mechs to put them in. If they're A/A mechwarriors, you may want to hire them anyway (up to 2) because they'll keep your mechs alive when no other pilots will. If you get more than 3 mechs, sell off the worst mech. Save your money until you can buy an Atlas (or 2, or 3,...) When weapons on your mechs are destroyed, then you can upgrade a little more cheaply -- you don't have to remove the old weapons/ammo first.

Customize WISELY! Think VERY carefully before just throwing lots of lasers on your mech and tearing into battle -- without a lot of heat sinks, your mech will be overheating, leaving you unable to fire. Most I.S. mech designs need more heat sinks anyway, so even replacing 1 large laser with a clan ER large laser and a heat sink won't be enough. Even 10 TONS of single heat sinks isn't enough for 1 clan ER large laser! For that reason, it is useless to put 4 PPCs and 4 LARGE LASERS on an ATLAS. Save your game, do a conversion, play a mission, then reload your game if it doesn't work. Repair the heat sinks, internal structure, destroyed ammo, and armor BEFORE customizing a mech -- or that mech will gain weight from "GHOST" items (a BAD BUG in the game)! A 1-slot exchange when customizing a mech will cost 50,000 C-Bills. Expect to spend around 500,000 C-Bills for each mech you customize. And you'll have to unconvert each mech before selling it, or lose irreplaceable clan weaponry. This MAY mean you'll never afford the Atlas that you've always wanted...

Include 1-4 jump-jets on your mech. More jump-jets is a waste of space and weight. Place them in the side torsos in almost equal numbers so if you lose a leg, both arms, and a side torso, you still have some mobility. Jump-jets aren't as critical for starmates and is rather UNHEALTHY for them on the space missions... (Can you say lemmings?)

The computer AI mechs tend to only fire 1 weapon at a time, which is nearly worthless if that weapon was a small laser. This is IMPORTANT when designing a starmate mech! One BIG GUN is better than 4 little ones. Starmate mechs should have max armor and a few deadly weapons to guarentee that's the weapons they're firing.

Inner Sphere's 3-slot Double Heat Sinks are better than single heat sinks because 10 heat sinks are inside the engine, taking up no critical slots on the mech. There's too few slots in the head, central torso, or the legs for even 1 IS double heat sink. If an IS mech has lower arm actuators, hands, and an XL engine, the most double heat sinks it can mount is 2 on each arm and 3 in each side torso for a total of 20 double heat sinks (10 in the engine) giving 40 heat dissipation units for 10 tons and 30 slots used. 30 single heat sinks could fit in the same NUMBER of slots, giving the SAME 40 heat dissipation units at a COST of 30 tons and 30 slots used. So, 10 double heat sinks offer a 20 ton weight savings (over 30 singles) for NO extra space! Use empty slots in the side torso sections (and legs for clan double heat sinks), to have extra heat-dissipation capacity even if you lose your arms. Your heat sinks should IDEALY be equal or GREATER than the heat generated by all the weapons fired at once on your mech.

XL engines weigh HALF as much as regular engines but take up 3 slots in each side torso (2 for clan). In battletech, after 3 engine hits, your mech is destroyed! Since 3 engine slots are in each side torso, losing 1 side torso can kill you! Clan mechs with XL engines are slightly safer. They can lose a side torso and still function, barely. Every engine hit increases your heat level a few points! With 2 engine hits, you could overheat just by walking around, if you only have 10 single heat sinks and you're on a hot world. This is why after a bad exchange with another mech, you just can't seem to fire as fast without overheating even though you have fewer weapons left...

XL engines are only practical on 50+ ton CLAN mechs and 70+ ton inner sphere mechs that have enough armor to protect their fragile side torsos! A 20 ton mech, clan or otherwise doesn't need a very big engine to move at 108 kph, and you can't afford to make it EASIER for enemies to kill you! Use a regular (non-XL) engine class, preferably one equal or just under 100, 200, or 300. The gyro on your mech weighs 1 ton per 100 of engine class. A 105 engine class needs a 2 ton gyro, while a 100 (or <100) engine class only needs a 1 ton gyro. On a big mech, this isn't a big deal, but on a little mech 1 ton can be useful. Smaller engines weigh less. Your lack of running speed is offset by jump jets.

If EXTRA weight is needed and lots of space is available ADD Endo-Steel to the arms. This HALVES the weight of the internal structure. Internal Structure weighs 1 ton PER 10 tons of mech weight. (A 100ton mech has a 10ton standard internal structure, or a 5ton Endo-Steel one.) Maxed-out, a 100ton mech needs just over 19 tons of Regular armor or 16 tons of Ferro-Fiberous armor (saving 3 tons for 7 used slots unlike endo-steel's savings of 5 tons for 7 used slots!) Do not put endo-steel OR Ferro-Fiberous anywhere other than the arms (except on IS mechs, which you don't have a choice), other MORE-IMPORTANT stuff needs the torso space! Use Ferro-Fiberous ONLY on a clan mech that needs lots of weight but doesn't need lots of space - and then only after adding Endo-Steel.

Place the FIRST ton of ammo for a FAST-firing weapon in an arm (saving space elsewere), you can PROBABLY use the ammo before you lose the arm! The FIRST ton of ammo for 1 weapon you place on a mech is ALWAYS the first ton of ammo used up by that weapon. If that ammo is in the arm, the ammo will be used up before the arm is destroyed - making critical ammunition hits unlikely at best. Don't refill the ammo until ALL ammo of that kind is used up, and then refill the ammo in the SAME order that it was placed on the mech. If you DON'T do this, you'll experience the ammo bug - your mech's weight will PERMANENTLY increase by 1 or more tons.

Since aiming beyond 300 meters is difficult, furious mech battles often occur closer than that. Multiple Gauss Rifles, PPCs, ARROW IVs, or ER anything is just a waste of space, weight, and HEAT! 1 or 2 long-ranged weapons is a GOOD idea, 5 or more is suicide!

LRM-15s have a slightly better damage to weight ratio than LRM-10s or LRM-20s. But clan LRM-5s have the best ratio of all LRMs -- 5 damage for a 1 ton (2 ton for IS) launcher.

The space and weight used by one Arrow IV is wasteful if your enemy is always less than 400 meters away, PLUS a single AMS can easily stop ARROW IVs! Use Streaks or LRMs instead in close-range combats, if aiming is a problem. Although the Arrow IV is the SLOWEST firing weapon in the whole game, it can trash a mech with a single hit. It's an extremely large (12 or 15 slots), heavy (12 or 15 tons) weapon that will only have a few shots (5 shots per ton of ammo). But if a Clan mech DOESN'T have an XL engine, a Clan Arrow IV can be put entirely in a side torso with the ammo for it in the other side (or legs). If an ARROW IV isn't your PRIMARY weapon, put all of its ammo and MOST of it in one arm and put max armor on the arm.

AMS is not as good a defense as everyone thinks, here's a newsgroup message on the subject: "when i had weapons in 5 different groups, had group fire on, and had lasers and AMS in the same group, group one, the AMS WOULD NOT FIRE against any incoming missiles! i tried switching over to the ams, and pressing the trigger while the ams was highlighted, and they still did not fire! (i had multiple ams systems, 2 to be exact) However, when i switched to chain fire i could fire the ams by highlighting and pulling the trigger, and they worked normally also....) ...turning ON and OFF is the AUTO-FIRE of AMS. BY default, it is suppose to be CRTL-A, but this does not work in Mercnet... problems with AMS is an enemy (here's a tip for Mercnet) can get within 850m and dumb-fire there missles at 850m in mid air and your AMS will detect the launch and fire away... One shot (i.e.1 SRM-2) from a small launcher or one large LRM20 shot acures, the AMS will fire a default (I think at last count) 50 rounds per launch. So someone with 4 launchers at once will cause the AMS to put out 200 rounds ... many test I have done with AMS is that I see no more protection from missles with AMS with more than ONE AMS!"

AMS will TRY to shoot down NUKES and ARROW IVs! You can MANUALLY single-fire the AMS to IMPROVE your chances of killing incomming missiles! What the above testing suggests to me is: only put 1 AMS on a mech, put it in it's own group (group 5 is best, that group couldn't be group-fired with a single keypress anyway...) only have 2-4 tons of ammo, might as well put the AMS and its ammo in an arm to save critical slots in the torso for something more valuable. IF someone's trying to drain your AMS with SRM-2 shots (or LRM-5 shots), hit CTRL+A. Hit \ and CTRL+A if your opponent then decides to use an ARROW IV. I've found that you need about 4-8 tons of AMS ammo to effectively counter the "missile boat".

NOTE!: AMS >CANNOT< be turned OFF in the single-player game! (a bug)

Arrow IVs are actually more useful against people than the computer. The computer is not relentless, and often gets stuck behind scenery. And computer mechs seldom stray more than 500 m from starting locations. True, the AMS can destroy ARROW IVs, but only one ARROW IV has to slip through the defenses to hurt a 100-ton mech very badly. Arrow IVs, being guided, will be one of the few weapons that's easy to hit with at VERY long range. It does not take skill to fire it, it simply takes skill to survive LONG enough to fire it again! And with 3 LRM-15s fired with a single ARROW IV, a targeted mech 950 meters can be peppered all over - AMS or no. And EVEN if the target mech has 14 LRM-20s, it can't return the favor because its LRMs won't get lock at 950m.

Grouped small pulse lasers are like machine guns, very fast fire but very low individual damage. And the ratio of damage to heat is terrible: 2 heat for 3 damage. Because of small pulse lasers incredibly fast rate of fire, even ER medium lasers probably wouldn't overheat a mech as fast. I suggest using ER small lasers instead. Rate of fire is still decent, but not too fast. Range is slightly improved. Damage is 5 instead of 3. And heat is the same. Plus they weigh half as much! I have a Firemoth design with 10 such ER small lasers and it kills mechs very effectively for its size, until something destroys it...

Even the lowly Gauss Rifle has its uses. At ranges beyond 600m, it's one of the FEW weapons that can hit a target. Rate of fire is low, but heat isn't a problem at all so heat sinks are unneccessary. Weight lost in the weight of the weapon is saved by needing fewer heat sinks.

What I'm getting at is ALL the weapons have strengths and weaknesses. And sometimes a weapon's strength IS its weakness, like high rate of fire! So the choice of weapons on a mech is mostly based on LONG / SHORT ranged weapons and personal preferance. All the weapons were designed to be balanced. Less powerful weapons ussually weigh less or have a higher rate of fire. Heavier weapons use up LOTS of critical space, and if they use ammo they have only a few shots per ton. And "superweapons" like the ARROW IV have glaring weaknesses - heavy, huge, slow-firing, and easily shot down by AMS.

James 3:5-10: My Reminder
And the tongue is a fire, a world of iniquity: so is the tongue among our members, that it defileth the whole body. Out of the same mouth proceedeth blessing and cursing. My brethren, these things ought not so to be.

ferro and endo are just armor.
Those will always be hit.. but first no not always.. machine guns and AC's bypass armor and hit internals.

James 3:5-10: My Reminder
And the tongue is a fire, a world of iniquity: so is the tongue among our members, that it defileth the whole body. Out of the same mouth proceedeth blessing and cursing. My brethren, these things ought not so to be.

This is allegedly how it works in MW2, can't say I ever tried checking it, but I always used endo/FF as padding after this. Not sure if it carried over to MW2:mercs, but would guess so.

"If you get hit in the back armor, critical areas take damage from the top of the list down. If you take damage to front armor criticals damage from the bottom of the list up."

On another matter, is it possible to change engine sizes or XL/std in single-player? I'm playing through now using 1.06 and the inability to do this is a pain in the bum. Everything else seems to be present; endo, FF, double-heatsinks.

-edit, just found in the 1.1 patch notes: "5) Engine type can now be modified in the Mercenaries Commander and Mercenaries games."

I do not use 1.1 because it screws up the sound for the dos version. Im running Win Vista 64 on my main rig. All my MW2 titles on this machine are the dos versions using MechVM.

For Mercs I am using 1.06 because anything later causes the game to screw up on this rig.

As for single player games, it doesn't really matter to me which engine type is used as long as the main customization takes. I also have a neat little set of programs for making Instant action/Multi play mechs for mercs. It's called mek2txt&txt2mek. Mek2txt turns your mek file into a txt file that you can examine and/or change at your convience. txt2mek can be used to turn it back into a viable mw2 mercenaries mek file You can also use notepad to write out the information and the program turns it into a useable mek file.

Its good for making quick adjustments to workable meks without having to use the mechlab when all you want to do is minor changes.

Edit: @Khorg Another thing that must be said for Single Player and XL engines. Xl Engines are not available at the Begining of the Sp campign game. You will have to keep reading the news articles at the comstar terminal to find out when they can be purchased etc....